Shaped articles of improved dyeability

ABSTRACT

A COMPOSITION OF IMPROVED DYE RECEPTIVITY COMPRISING A POLYMER CAPABLE OF BEING FORMED INTO SHAPED ARTICLES AND A SULFONATED ARYL PHOSPHATE OR AN ARYL PHOSPATE ALKALI METAL SULFONATE.

United States Patent Ser. No. 70,552

Int. Cl. C08b 21/04 US. Cl. 106--177 6 Claims ABSTRACT OF THE DISCLOSUREA composition of improved dye receptivity comprising a polymer capableof being formed into shaped articles and a sulfonated aryl phosphate oran aryl phospate alkali metal sulfonate.

This application is a divisional of US. application Ser. No. 468,581filed June 30, 1965.

This invention relates to the production of shaped articles havingimproved receptivity for disperse and/or basic dyes.

There exists a wide variety of polymers possessing certain desirableproperties which make them useful when formed into shaped articles suchas filaments or films but which are relatively diflicult to dye to usedisperse dyes, basic dyes or both classes of dyes. The use of dyes fromeach of these classes involves a combination of processing and productadvantages as well understood in the art. However, shaped articlesprepared from certain types of polymers often cannot be colored in deepshades with one or both of these classes of dyes because of poorreceptivity for such dyes. Thus any method used to obtain an improvementin the receptivity of shaped articles such as filaments for one or bothof these classes of dyes where such receptivity is presently less thandesirable, is much to be desired. It should be noted in this connectionthat there are very few shaped articles prepared from a spinning dope ormelt which possess adequate receptivity to both disperse and basic dyes.

In accordance with one aspect of the invention, a polymer capable ofbeing formed into shaped articles such as filaments or films having lessthan completely ade quate receptivity for disperse and/ or basic dyes,is shaped to form such articles in the presence of a sulfonated arylphosphate, i.e., an aryl phosphate in which one or more aryl hydrogenatoms is substituted with a sulfonate group. If the polymer is beingformed into shaped articles such as filaments by means of melt extrusiontechniques, the phosphate may be incorporated into the melt prior toextrusion. When it is desired to dry or wet extrude the polymer, thephosphate may be mixed with the spinning dope or solution prior toextrusion. While the mechanism by which the polymers are rendered moredye receptive is not known, it is thought that the sulfonated arylphosphate does not chemically combine with the polymer.

The sulfonated aryl phosphates contemplated under this invention may beprepared for example by reacting the unmodified aryl phosphate withsulfur trioxide, the latter preferably in the form of a solution in aninert solvent such as ethylene chloride. Specific conditions for thepreparation of these compounds are shown in US. Pat. 3,549,729 whichissued on a continuation of application Ser. No. 468,612, filed June 30,1965, now abandoned, by Joseph Di Pietro and Merrill N. OBrien, Jr. andassigned to the same assignee as this aplication.

A particularly important group of phosphates which may be utilized underthis invention are the sulfonated triaryl phosphates, e.g., any of thefollowing compounds containing one or more sulfonate groups substitutedfor Patented Nov. 21, 1972 an aryl hydrogen atom: triphenyl phosphate,tricresyl phosphate, o-phenylphenyl bis(phenyl) phosphate, tris-(o-phenylphenyl) phosphate, tri(2,5 dimethylphenyl) phosphate, tri(2,6dimethylphenyl) phosphate, tri(3,5- dimethylphenyl) phosphate, tri(2,3,5dimethylphenyl) phosphate, tri(beta-naphthyl) phosphate, the dialkylmonoaryl phosphates such as dimethyl monophenyl phosphate and diethylmonophenyl phosphate, the di-aryl monoalkyl phosphates such as diphenylmonomethyl phosphate and dicresyl monomethyl phosphate, and the bisphosphate of alkylene glycols and dialkylene glycols such as bis(dicresyl phosphate) of diethylene glycol. Sulfonated aryl phosphatescontaining at least one aryl group of multiple ring structure, e.g.phenyl phenyl such as o-phenylphenyl, are preferred.

The sulfonate groups in the sulfonated aryl phosphate added to thepolymer melt or dope may be in the free acid form but are preferably inthe form of a salt, most suitably an alkali metal salt, e.g., ofpotassium or sodium.

The sulfonated aryl phosphate employed in the process of this inventiongenerally contains from one to about six sulfonate groups, preferablyfrom one to about three sulfonate groups from each benzene ring in thecompound.

The sulfonated aryl phosphate is used in an amount such that a minorportion of the compound remains dispersed throughout the cross sectionof the shaped article, e.g., the individual filaments. In many cases theamount of phosphate in the shaped article will be in the range of about1 to 10%, preferably 3 to 6% by weight.

The invention may be applied to a wide variety of polymers which may beformed into shaped articles such as filaments having less than thedesired degree of receptivity for disperse and/or 'basic dyes. Aparticularly significant group of polymers to which this invention maybe applied are the olefin polymers which are not easily dyed withdisperse or basic dyes, e.g. polypropylene, poly- 3-methyl butene-l,poly-4-methyl pentene-l, polyethylene as well as copolymers ofpropylene, S-methyl butene-l, 4-methyl pentene-l, or ethylene with eachother or with minor amounts of other olefins, e.g. copolymers ofpmpylene and ethylene copolymers of a major amount of 3-methyl butene-land a minor amount of a straight chain n-alkene such as n-octene-l,n-hexene-l, n-hexadecene-l, n-octadecene-l, or other relatively longchain alkenes, as well as copolymers of 4-methyl pentene-l, and any ofthe same n-alkenes mentioned previously in connection with B-methylbutene-l. These polymers are generally formed into filaments and filmsby melt extrusion.

Another very important group of polymers are the fiber-forming linearpolyesters of polyhydric alcohols, e.g. glycols such as ethylene glycol,diethylene glycol, dimethylol cyclohexane and the like or mixturesthereof with polycarboxylic acids, e.g. dicarboxylic acids such asterephthalic acid, phthalic acid, isophthalic acid, 5-sulfoisophthalicacid, adipic acid and the like and mixtures thereof, as well asfiber-forming linear polyesters of hydroxycarboxylic acid, e.g.polyglycolic acid. A particularly important material within this groupis polyethylene terephthalate. The polymers are generally meltextrudable.

Another group of polymers which may be formed into shaped articles ofimproved disperse and basic dyeability under this invention are theoxymethylene polymers. While oxymethylene homopolymers are contemplated,the preferred oxymethylene polymer is a random oxymethylene copolymer,i.e., one which contains recurring oxymethylene, i.e., -CH O-, unitsinterspersed with groups in the main polymer chain where R is a divalentradical containing at least two carbon atoms directly linked to eachother and positioned in the chain between the two valences, with anysubstituents on said R radical being inert, that is, those which do notinclude interfering functional groups and which will not induceundesirable reactions, and wherein a major amount of the -OR- unitsexist as single units attached to oxymethylene groups on each side. Arandom copolymer may thus be distinguished over a block copolymerwherein repeating units of each monomer make up block segmentscontaining little or no units of any other monomer. Thus, in blockcopolymers containing oxymethylene and other units, susbtantially all ofthe other units are attached to like units rather than oxymethyleneunits on each side. Particularly preferred are random copolymers whichcontain from 60 to 99.6 mol percent of recurring oxymethylene groups. Ina preferred embodiment R may be, for example, an alkylene or substitutedalkylene group contining at least two carbon atoms. Examples ofpreferred polymers include copolymers of trioxane and cyclic etherscontaining at least two adjacent carbon atoms such as the copolymersdisclosed in U.S. Pat. No. 3,027,352 of Walling et al.

The preferred random oxymethylene copolymers included within thisinvention are thermoplastic materials having a melting point of at least150 C. and are normally millable at a temperature of 200 C. They have anumber average molecular weight of at least 10,000. These preferredpolymers have a high thermal stability. For example, if the stabilizedoxymethylene polymer used in a preferred embodiment of this invention isplaced in an open vessel in a circulating air oven at a temperature of230 C. and its weight loss is measured without removal of the samplefrom the oven, it will have a thermal degradation rate of less than 1.0wt. percent/min. for the same period of time.

The preferred random oxymethylene copolymers have an inherent viscosityof at least one (measured at 60 C. in a 0.1 weight percent solution inp-chlorophenol containing 2 weight percent of a-pinene). The preferredcopolymers of this invention exhibit remarkable alkaline stability. Forexample, if the preferred copolymers are refluxed at a temperature ofabout 142 C.145 C. in a 50% solution of sodium hydroxide in water for aperiod of 45 minutes, the weight of the copolymer will be reduced byless than one percent.

As used in the specification and claims of this application, the termcopolymer means polymers having two or more types of monomeric units,including terpolymers and higher polymers. Suitable oxymethyleneterpolymers are those having more than two different kinds of monomericunits such as those disclosed in U.S. patent application Ser. No.229,715, filed Oct. 10, 1962 by Walter E. Heinz and Francis B. McAndrew,which application is assigned to the same assignee as the subjectapplication. Oxymethylene polymers are usually formed into shapedarticles by melt extrusion.

Another group of polymers which may be formed into shaped articles ofimproved disperse and basic dye receptivity in accordance with theinvention are the cellulose esters and an especially significant classof cellulose esters are the cellulose triesters of fatty acids such asacetic, formic, propionic, butyric and the like which contain fewer thanabout 0.29, and preferably fewer than about 0.12 free hydroxyl groupsper anhydroglucose units in the cellulose molecule. A particularlyimportant material within this group is cellulose triacetate containingmore than 59% and preferably more than 61% of acetyl groups calculatedas combined acetic acid. Cellulose triacetate is generally dry extrudedfrom solution in the solvent comprising a major amount of halogenatedalkane, e.g. a mixture of 90% of methylene chloride and of methanol toform shaped articles such as filaments and films.

The invention may also be applied to cellulose esters containing morethan 0.29 hydroxyl groups per anhydroglucose unit, e.g. celluloseacetate containing 54-56% of acetyl groups calculated as combined aceticacid. Secondary cellulose acetate is generally dry extruded fromsolution in acetone to form shaped articles such as filaments and films.

Other polymers contemplated under this invention for the improvement ofdye receptivity are fiber-forming polyamides such as poly(polymethylene)terephthalamides, adipamides and sebacamides in which the polymcthylenegroups contain 2 to 8 carbon atoms, e.g. polyhexamethyleneterephthalamide and polyhexamethylene adipamide, polyaminoalkanoic acid,e.g. polyaminocaproic acid, fiberforming polyurethanes such as thepolyurethane formed from the bis(chloroformate) of butanediol andtetramethylene diamine, fiber-forming polymers and copolymers ofacrylonitrile, e.g. containing more than 40 percent and preferably morethan percent of acrylonitrile residues in the polymer chain, e.g.polyacrylonitrile and copolymers of acrylonitrile and variouscomonomers, e.g. vinyl esters such as vinyl acetate, vinyl amines, vinylpyridine, methyl vinyl pyridine, chloroethyl vinyl ethers, etc., andfiber-forming polymers of vinylidene cyanide such as those containing atleast 50 mol percent of vinylidene cyanide in the polymer chain, e.g. acopolymer of 50 mol percent vinylidene cyanide and 50 mol percent ofvinyl acetate.

The disperse dyes which are more easily applied to filamentary materialas a result of this invention are generally non-ionic compounds whichare applied in the form of a dispersion in an aqueous bath. These dyeshave long been applied to secondary cellulose acetate and include azodyes, anthtraquinone dyes and aryl amine dyes.

The basic dyes contemplated also include azo dyes, anthraquinone dyesand aryl amine dyes and form cations in aqueous solution capable ofattachment to acidic or anionic dye sites on the substrate to be dyed.

The following examples further illustrate the invention:

EXAMPLE I A sample of tris-(o-phenylphenyl) phosphate (55 g.) in 150 ml.of ethylene chloride is placed in a flask. Liquid S0 (24 g.) in ethylenechloride is slowly added to the mixture, which is kept at 5-10 C. andconstantly stirred. During this addition small amount of fibrouscrystals are formed. The reaction mixture is transferred into aseparatory funnel and extracted with n-heptane. The bottom oil layer isadded to a K CO solution, followed by addition of a KCl solution. Awater white crystalline solid is obtained which analysis showed to betris-(o-phenylphenyl) phosphate mono (potassium sulfonate).

To a sample of 5 g. of a stereospecific copolymer of 3-methyl butene-land 1.5 mol percent n-hexadecene is added 0.25% by weight of a heatstabilizer and 5% by weight of tris-(o-phenylphenyl phosphate)mono(potassium sulfonate) prepared as described above, based on theweight of the polymer. The sample was dried under vacuo at 60 C. andthen it was melt extruded through an orifice of about 15 mils at 350 C.,to produce fibers which are taken up at a speed such that they are drawndown to about 8 to 10 denier per filament.

The sample was also present between hot plates at about 350 C. toproduce a film of about 0.1 to 0.15 mil thickness.

These fibers and films possess receptivity for disperse and basic dyes,whereas fibers spun in the same way from the same copolymer but withoutthe sulfonate do not possess such receptivity. The comparative tests fordisperse and basic ciyeability are carried out as follows:

In the case of disperse dyeability, mg. of filament or film sample isagitated for 2 hours in 300 m1. of an aqueous dyebath at 97 C.containing g./l. of Igepon T-77 surfactant [sodium fatty methyl tauride,C17H33 Co-'N(CH C H SO Na], /2 g./l. of Calgon (sodiumhexametaphosphate) and mg. of a disperse dye such as Eastman Fast BlueBGLF (Cl. Part II No. 60767),

S Eastman Blue BNN ((3.1. Part H No. 61505) or Celliton Pink BA-CF (0.1.Part II No. 60710). The sample is then washed and dried.

For basic dyeability, the same procedure as that described above fordisperse dyeability is usedexcept that dye used is a basic dye such asSevron Blue B (C.-I. Basic Blue 2) or Sevron 'Brillian Red B (CJ.Disperse' Red 15) and before dyeing, the pH of the dyebath is decreasedto about 4.5 with sodium acetate and acetic acid.

The relative degree of dye uptake is determined both by visualappearance of the sample and by study of the cross-section of thefilament or film with a polarizing microscope to determine the degree ofpenetration of the dye.

The foregoing tests show that the sample containing the aryl phosphatesulfonate picks up a greater amount of both disperse and basic dye thanthe sample containing no sulfonate.

EXAMPLE II The procedure of Example I is repeated except that thepolymer which is melt spun is stereospecific polypropylene. Similarresults are obtained.

EXAMPLE III The procedure of Example I is repeated except that thepolymer which is melt spun is polyethylene. Similar results areobtained.

EXAMPLE IV The sulfonation procedure of Example I is repeated exceptthat 48 g. of liquid S dissolved in 160 cc. of ethylene dichloride isadded to the phosphate and the reaction is carried out at 40 C. for 4 /2hours. The

product is analyzed to be tris(o-phenylphenyl) phosphate tri(potassiumsulfonate) which is thermally stable to 350 C.

The melt spinning procedure of Example I is repeated with thetrisulfonate of this example. The fibers have improved receptivity todisperse and basic dyes.

In accordance with another aspect of the invention, a minor amount of anunsubstituted, unmodified aryl phosphate is blended into the polymerwith the sulfonated aryl phosphate to obtain an increased enhancement ofdye receptivity, better homogeneity of the shaped article and improvedevenness of dyeing, i.e. less streakiness.

The unsubstituted aryl phosphate may be any of the aryl phosphatesmentioned previously, which when containing sulfonate groups aresuitable for the sulfonated aryl phosphates of this invention, and maybe used for example in an amount of about 3 to 10% based on the weightof the polymer.

Examples V, VI and VII illustrate the use of an unsubstituted arylphosphate with the sulfonated aryl phosphate of this invention.

EXAMPLE V The sulfonation procedure of Example I is followed except thatthe aryl phosphate subjected to the described sulfonation treatment is0.05 gram mol of tris-(betanaphthyl) phosphate, the S0 is added as asolution of 32 g. (0.4 mol) in 150 cc. of 1,1,2-trichloroethane and thereaction is carried out at a temperature of 10-15" C. for 2% hours. Theproduct is analyzed to be tris(betanaphthyl) phosphate penta(potassiumsulfonate) and is thermally stable to 350 C.

The spinning procedure of Example I is followed except that 5% by weightof the pentasulfonate together with 5% by weight of n-octyl phenyldicresyl phosphate and 0.25% by weight of a heat stabilizer, all basedon the weight of the polymer, are blended with the copolymer of B-methylbutene-l and n-hexadecene prior to melt spinning.

The fibers obtained have improved receptivity for disperse and basicdyes.

EXAMPLE VI EXAMPLE VII The procedure of Example V is followed exceptthat the unsubstituted aryl phosphate is tris-(beta-naphthyl) phosphaterather than n-octylphenyl dicresyl phosphate. Similar results areobtained.

EXAMPLE V-III vThe procedure of Example I is followed except that thepolymer is a fiber-forming polyethylene terephthalate. Fibers havingimproved receptivity for disperse and basic dyes are obtained.

EXAMPLE IX The procedure of Example I is followed except that thepolymer blended with the sulfonated aryl phosphate is a randomoxymethylene copolymer, i.e., a copolymer of trioxane and 2 weightpercent based on the polymerizable mixture of ethylene oxide prepared asdescribed in US. Patent No. 3,027,352 and after-treated to removeunstable groups as described in application Ser. No. 102,- 096, filedApr. 11, 1961. Before being mixed with the sulfonated aryl phosphate,the copolymer is further stabilized by blending with 0.5 weight percentof 2,2'-methylcne bis l-methyl 6-tertiary butyl phenol) and 0.1 weightpercent of cyanoguanidine based on the weight of the polymer.

The fibers obtained have improved receptivity for disperse and basicdyes.

EXAMPLE X The procedure of Example I is followed except that thefiber-forming polymer is cellulose triacetate containing about 61.7% ofacetyl groups calculated as combined acetic acid which, together withthe 5% of sulfonated aryl phosphate based on the weight of thetriacetate, is dissolved in a spinning solvent consisting of 91% byweight of methylene chloride and 9% by weight of methanol to yield aspinning dope containing about 21.5% by Weight of triacetate. Thisspinning dope is dry spun to yield fibers containing the sulfonated arylphosphate distributed throughout their cross-section which have improvedreceptivity to disperse and basic dyes.

EXAMPLE XI The procedure of Example I is followed except that thefiber-forming polymer is secondary cellulose acetate containing about54.6% of acetyl groups calculated as combined acetic acid which,together with about 3% of the sulfonated aryl phosphate described inExample I, based on the weight of the secondary acetate, is dissolved inacetone to form a spinning dope containing about 22% by weight of thesecondary acetate.

The spinning dope is dry spun to yield fibers of secondary celluloseacetate containing the sulfonated aryl phosphate dispersed throughoutits cross-section, which have improved receptivity to basic dyes.

EXAMPLE XII The procedure of Example I is followed except that thefiber-forming polymer is polyhexamethylene adipamide. After beingblended with the sulfonated aryl phosphate, the polymer is melt spun toyield fibers having improved receptivity to disperse and basic dyes.

EXAMPLES XIII TO XVI The procedure of Example I is followed except thatthe aryl phosphate being sulfonated is (XIII) triphenyl phosphate, (XIV)n-octyl phenyl dicresyl phosphate, (XV) tricresyl phosphate, and (XVI)tris-(phenanthryl) phosphate to obtain the corresponding potassiumsulfonate, of which is blended with the copolymer of 3- methyl butene-land n-hexadecene as described in Example I. The mixture is then meltspun into fibers, each of which has improved receptivity to disperse andbasic dyes.

The sulfonates described in the foregoing examples are analyzed forchemical structure (1). by obtaining the infrared adsorption spectrum todetermine the presence of a phosphate bond; (2) by determining thepercent carbon, hydrogen, phosphorus, sulfur and oxygen using standardanalytic procedures to determine whether the structure of the initialaryl phosphate is still intact and the probable number of sulfonicgroups substituted; and (3) by reacting free sulfonic acid form of thesulfonated aryl phosphate with PO1 and then with ammonia (which formssulfonamide groups from sulfonic acid) and then analyzing the compoundto determine Whether equimolar proportions of sulfur and nitrogen arepresent, which indicates the presence of sulfonic acid groups in thecompound reacted with the PCl Although the foregoing examples eachdescribe the spinning of fibers, it is to be understood that thisinvention may also be applied to-the production of such shaped articlesas films by extrusion or casting from a melt or solution, and to moldedarticles produced, for example, by injection, compression or blowmolding, which products all have improved receptivity to basic anddisperse dyes.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that many variations may be madetherein without departing from the spirit of my invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A composition of improved dye receptivity consisting essentially ofpolymers of cellulose esters of saturated fatty acids containing from 1to 4 carbon atoms capable of being formed into shaped articles and from1 to percent by weight, based on the weight of the polymer, of preformedsulfonated aryl phosphate.

2. A composition of improved dye receptivity consisting essentially ofpolymers of cellulose esters of saturated fatty acids containing from 1to 4 carbon atoms capable of being formed into shaped articles and from1 to 10 percent by weight, based on the weight of the polymer, ofpreformed aryl phosphate alkali metal sulfonate.

3. A composition of improved dye receptivity consisting essentially ofpolymers of cellulose esters of saturated fatty acids containing from 1to 4 carbon atoms capable of being formed into shaped articles and from1 to 10 percent by weight, based on the weight of the polymer, ofpreformed sulfonated aryl phosphate at least one aryl group of which iscomposed of at least 2 aromatic ring structures.

4. A shaped article having improved receptivity to disperse and basicdyes, consisting essentially of polymers of cellulose esters ofsaturated fatty acids containing from 1 to 4 carbon atoms, and from 1 to10 percent by weight, based on the weight of the polymer, of preformedsulfonated aryl phosphate.

5. Filamentary material having improved receptivity to disperse andbasic dyes consisting essentially of polymers of cellulose esters ofsaturated fatty acids containing from 1 to 4 carbon atoms, and from 1 to10 percent by weight, based on the weight of the polymer, of preformedsulfonated aryl phosphate.

6. A composition of improved dye receptivity consisting essentially ofpolymers of cellulose esters of saturated fatty acids containing from 1to 4 carbon atoms, capable of being formed into shaped articles, from 1to 10 percent by weight, based on the weight of the polymer, ofpreformed sulfonated aryl phosphate, and from 3 to 10 percent by weight,based on the weight of the polymer, of preformed unsubstituted arylphosphate.

References Cited UNITED STATES PATENTS 3,558,579 1/1971 Di Pietro l06177X 3,549,729 12/1970 Di Pietro et al. 260947 2,071,354 12/1937 Morgan260947 3,432,472 11/1969 Caldwell 26O-75 T THEODORE MORRIS, PrimaryExaminer US. Cl. X.R. l06193; 26067, 75, 77.5, 85.5, 88.2, 88.7

